Acting on intelligence provided by the U.S., Mexican police just missed capturing the world's biggest drug kingpin in a beach resort popular with American tourists 24 hours after Secretary of State Hillary Clinton and dozens of other foreign dignitaries were attending meetings in the same town.

Mexican federal police nearly grabbed Joaquin "El Chapo" Guzman, head of the powerful Sinaloa drug cartel, during a late February raid on a mansion in Los Cabos, a tourist area at the southern tip of Baja California. U.S. officials confirmed to ABC News that they provided Mexican authorities with the information that led to the raid. While Guzman escaped, four people were arrested at the house and are in Mexican custody.

The operation to capture Guzman began on Feb. 21, a day after Clinton and other foreign dignitaries were in Los Cabos for meetings of the G20 nations, the countries with the world's 20 top economies. Two-and-a-half million tourists visit the area annually, the majority of them American.

Guzman, whose nickname means "Shorty," has long been ranked among the richest men in the world by Forbes, and the DEA says he has surpassed late Colombian drug kingpin Pablo Escobar in power. The U.S. Department of the Treasury calls him "the most powerful drug trafficker in the world." The State Department has offered $5 million for his capture.

Though Guzman was arrested in 1993, he has been on the loose since escaping from prison in a laundry truck in 2001. Now in his 50s, he built the Sinaloa cartel into what law enforcement officials consider the most powerful drug trafficking organization in the world. Based in Culiacan, Sinaloa, the cartel has taken control of drug trafficking in much of western Mexico, including the states of Baja California, Sonora and Durango, while the violent Zetas gang, which includes many gunmen with Mexican military training, dominates the east. The Sinaloa cartel deals in methamphetamine, marijuana, heroin and Colombian cocaine.

The Mexican government was thought to be zeroing in on Guzman ahead of July's presidential election. His capture would boost the fortunes of the ruling PAN party, which is trailing the PRI party in the polls. Current president and PAN leader Felipe Calderon, who is not permitted to run for reelection, launched the ongoing anti-cartel war in which 50,000 people have died.

The Calderon administration had been accused of favoring the Sinaloa cartel while attacking lesser drug organizations. National Public Radio aired reports alleging that Mexican officials were helping the Sinaloa cartel to take control of areas run by other gangs. NPR also charged that arrest data showed that Sinaloa cartel members were arrested at a lower rate than members of other cartels. The Mexican government has disputed the charges.